Plumbers & Sewer Cleaning Companies

Know whats below

Know what’s below, call before you clear.

Union Gas, residents, plumbers and municipalities all have a role to play to prevent dangerous consequences of unintended cross bore intersections. For us, it’s a safety issue, plain and simple.

Union Gas, residents, plumbers and municipalities all have a role to play to prevent dangerous consequences of unintended cross bore intersections. For us, it's a safety issue, plain and simple.

What contractors and plumbers need to know

It is important that plumbers and sewer cleaning contractors are certain a natural gas line has not intersected a sewer line before an attempt is made to clear using motorized drain cleaning or high pressure water jetting equipment.

Here is more information and suggestions:

  • A Sewer Safety Inspection request is treated as an emergency (loss of service) call with a targeted response time of 1-2 hours.
  • A best practice is to call Ontario One Call as soon as you receive the call from your customer. This means our service provider can be onsite and have the investigation well underway (or even completed) when you arrive.
  • Over 90 per cent of calls are resolved quickly with a "Proceed" issued based on records check or proximity calculations.
  • In problematic investigations, our service provider representative will work closely with the drain-cleaning person to determine this proximity whenever possible.
  • If they cannot find where the sewer exits the building or if they suspect that there may be a cross bore, they will arrange to have a video inspection completed to see if a natural gas line has intersected the sewer.

Why it's important to be safe

There have been more than 20 incidents in the U.S. where natural gas released from a damaged line travelled through a sewer line into a structure and resulted in explosion and fire.

While there have been no incidents reported in Canada, Union Gas has found cross bores in our system.

The Utility Cross Bore Safety Program has been designed to specifically deal with this risk, and is compliant with the August 2011 TSSA code amendment to CSA Z662.

We are in this together

There has been great response from plumbers and sewer cleaning companies regarding our Utility Cross Bore Safety Program, and this bodes well for the future. But it's important we all stayed informed and the lines of communication remain open.

Union Gas has developed a multi-tiered approach to make the public aware of the safety risks of damaging a gas line as a result of a sewer cross bore.

We’ve compiled a list of all plumbers and drain cleaners within our franchise area and sent them information to highlight safety issues.

What about video?

Some plumbers have asked if they can use their own video equipment to ensure a cross bore is not present before clearing. This is not a recommended practice for several reasons:

  • In a blockage situation, video from the structure is usually ineffective as it is impossible to see beyond a blockage to the cause. The Union Gas video investigation often involves a launch from the sewer main and up the lateral from the street side.
  • A cross bored utility line is rarely the direct cause of a blockage. Often the damage caused by a cross bore has allowed roots or other obstructions to infiltrate the sewer line leading to an eventual blockage.
  • Even if an obstruction is visible, it is difficult to determine it is a gas line. Union Gas has used several different materials for gas lines over the decades and each has different colour characteristics.

Safety tips

  • Always contact Ontario One Call at 1-800-400-2255 to report a blocked sewer and request a Sewer Safety Inspection before attempting to clear with motorized drain cleaning or high pressure water jetting equipment if the blockage is beyond the four walls of the structure.
  • The Union Gas Cross Bore Program has been developed to mitigate the risk when using rotating equipment or the water jetting tools to clear a blocked sewer lateral.
  • If a cross bore has damaged a sewer lateral, it does not pose a safety risk unless rotating equipment such as an auger, or eel, or snake, is put into the sewer to clear a blockage.
  • Pressurized water jetting equipment can also damage a gas line.




Cross Bore Diagram


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